Sea surface
temperature (SST) anomalies during November 2009 continued to increase across
much of the central and eastern equatorial Pacific Ocean (Fig. T18).Consequently,
all of the monthly Niņo-region
SST indices were above +1.3°C, except for the Niņo1+2 index, which increased
to +0.5°C
(Table T2,
Fig. T5). The oceanic
thermocline, measured by the depth of the 20°C isotherm,
remained deeper than average across the equatorial Pacific (Figs. T15,
T16), with sub-surface temperatures in the
eastern Pacific reaching +4°C
to +6°Cabove average (Fig.
T17). Overall,
the oceanic and atmospheric anomalies reflected
a moderate strength El Niņo.

The
tropical circulation during November also featured intra-seasonal activity
associated with the Madden-Julian
Oscillation (MJO)
(Figs. T12),
which masked the El Niņo-related pattern of enhanced convection over the
central equatorial Pacific (Figs. T25
and E3). The MJO also
contributed to the variations of the lower-level
and upper-level wind anomalies over the equatorial Pacific (Figs. T20, T21 and
T13).

For
the latest status of the ENSO cycle see the ENSO Diagnostic Discussion at: